i included a mobo and psu in both lists capable of crossfire just to give you that option. if you don't think you'll want to add a second card though, the totals of both lists can be reduced by going with a lower wattage psu.

The main reason for build 1 is that the reviews I've seen of the 1055t show that a Phenom X4 will outperform it in games, which is the main purpose of your build. You'd be spending more money on a processor that will perform less on games.